Cable connecter



m L f pr 6 0 m um M enm m Vm A Ina s H H m log March 15, 1938.

Patented Mar. 15, 1938 PATENT OFFICE CABLE CONNE CTER.

Harold F. Crotty, Boston, Mass, assignor to Gen eral Electric Company, acorporation of New York Application January 17, 1936, Serial No. 59,581

3 Claims.

My invention relates to protective casings for electrical devices andconcerns particularly arrangements for bringing electric cables into me-1 ter-protective casings and providing a sealed mechanical connectionbetween the cable and the casing.

It is an object of'my invention to provide a joint between an electriccable and an electricaldevice casing which is both tamperproof and form,I utilize a casing having circular openings of predetermined uniformsizefor receiving electric cable and I provide removable nipples andwashers fitting the openings in the casing and adapted to compressgaskets of resilient material around the cable where it enters the wallof the casing.

The invention will be understood more readily from the followingdetailed description when considered in connection with the accompanyingdrawing, and those features of the invention which are believed to benovel and patentable will be pointed out in the claims appended hereto.In the drawing, Fig. 1 is a front elevation of a meter casing employingcable connections embodying my invention; Fig. 2 is an exploded view ofthe cable connections in Fig. 1 showingonly a fragment of the wall ofthe meter casing; and Fig. 3 is a top view partially in cross section ofthe apparatus of Fig. 2

' Like reference characters are utilized in the drawing to designatelike parts throughout. The

drawing illustrates the application of my invention to a meter casingalthough the invention may be employed for sealing cable entrances inany type of casing, including protective casings for instruments,relays, switches, and other electrical devices. I r

Preferably, Iprovide circular openings ll of a predetermined uniformsize in the walls l2 of a casing,lsuch as a meter casing it, intended Ito receive electric cable It for making electrical connections to anelectric meter I5 within the casing I3. A resilient gasket or bushing I6is provided, having an opening ll adapted to conform substantially inshape to the cable M which is being used. The gasket i6 is fittedagainst a removable nipple I8, which is adapted to cover the opening IIin the casing wall l2. Preferably, a cupped and shouldered washer I9 isprovided in order to have a removable member against which the resilientgasket 16 may be pressed by the nipple l8. In order to provide betterprotection for the resilient gasket i6 and to prevent unauthorizedpersons from gaining access to the meters of the casing I: by forcing aninstrument in between the cable l4 and the gasket l6 or by breaking outa portion of the gasket i6,

a, concave metal bushing .20 may be provided conforming in shape to thegasket l6 and the inner surface of the nipple i8 and having an opening 2l quite closely fitting the cable I.

The washer I9 is so arranged as to make a close fitting joint with thecasing wall I! and is so arranged as not to be pushed through theopening ll when the nipple I8 is clamped against the wall iii. Forexample, a ground and beveled joint may be provided,- or both theopeningH and the portion 22 of the washer I9 may be cylindrical and the washeri9 may be provided with a rim 23 to form a shoulder 24 abutting againstthe edge of the opening ll. 'I'he nipple It may be recessed at 25 to fltthe rim 2! in the cupped washer l9, If desired, the washer l9 or thenipple l8 may berabbeted and a ridge may be provided on the edge of theopening II as described in the copending application of Thomas A.Abbott, filed January 17, 1936, Serial No. 59,594, and assigned to thesame assignee as the present application. The cupped portion 26 of thewasher I 9 opens in a direction opposite to the direction in which theshoulder 24 abuts against the casing wall I! in order that clamping thenipple l8 against the wall 12 will simultaneously compress the gasket itagainst and into the washer l9 and hold the washer I 9 against the walll2.

The gasket 16 is preferably so shaped as to conform substantially to theshapes of the cupped washer l9 and of themetal bushing 20 or of theinner surface of the nipple l8; but the gasket I6 is of such thicknessthat, clamping the nipple l8 against the casing wall l2 tends tocompress the material of the gasket I6 and force it tight ly against thecable I so' as to grip the cable I! tightly and make a tight joint aswell as making a tight joint with the washer l9 While any suitableresilient and durable material may be employed for the gasket 16, I havefound rubber or a rubber composition to besatisfactOry. If desired, themetal bushing 20 may have stifiening grooves 2'! pressed into it.

Any suitable means may be provided for fastening or clamping the nippleI8 to the casing wall i2 over the opening H. For example, the nipple l8may be so shaped as to provide wings 23 containing bolt holes 29 forbolts 30 adapted to enter bolt holes 3| in the casing wall I2.Preferably, the bolt holes 3| are not threaded but receive the bolts 30loosely, and nuts 32 are provided permitting the assembly to betightened from the inside.

The bolts 30 have their heads 33 non-cylindrical, being flattened at thesides 34, and portions of the wings 28 adjacent the bolt heads 33 aresunk to form straight sided recesses 35 receiving the bolt heads 33 andpreventing them from turning. When the bolts 30 are drawn tight bytightening the nuts 32 from the inside of the casing l3, neither thenipples i8 nor the cable It can be removed without opening the casing i3to loosen the nuts 32. It will be understood that casings such as thatshown at l3 are ordinarily provided with sealing and locking means, notshown, so that the cover 36 cannot be removed by unauthorized persons,or, at least, cannot be removed without destroying some part of theapparatus, disclosing to inspectors or meter readers that the apparatushas been tampered with.

, In the drawing, nipples 18 are shown connected to the meter casing l3at the top and bottom, but it will be understood that any number ofnipples may be used and may be attached to sides or back as well as tothe top and bottom of the casing. Different sizes or shapes of cable maybe accommodated merely by replacing the relatively inexpensive bushingsiG-and 20 with others having suitably shaped openings therein. Even verygreat differences in size of cable to be attached may be taken care ofby providing nipples l8 and washers IS with diflferent internaldiameters,,permitting the power companies to limit their stocks ofcasings l3, the most expensive part, to only one style. In cases wherecable of only one size and shape is ever to be accommodated, the washeri9 may be made integral with the casing wall l2 arid the metal bushing20 may be made integral with the nipple l8; that is, the washer I9 andthe bushing 20 may be eliminated by-correspondingly shaping the openingsin the wall l2 and :the nipple I8.

The cable II, it will be understood, comprises one or more conductors 31surrounded by individual insulation 38. Preferably, additionalinsulation 39 surrounding all the conductors 31 is provided. Theinsulation 33 is then wrapped or encased in one or more layers 40 ofvery tough wear and force resistant material if desired, with a wrappingof metallic wires interposed. The cable H is therefore, suflicientlyprotected to serve the same purpose as a conduit. The conductors 31 areelectrically connected to terminals of the meter l inside the casing l3in a manner which constitutes no part of my invention.

In accordance with the provisions of the patent statutes, I havedescribed the principle of operation of my invention together with theapparatus which I now consider to represent the best embodiment thereofbut I desire to have it understood that the apparatus shown is onlyillustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is:

1. A cable .bushing arrangement for an electrical-device casing having awall with a cablerecelving opening therein, said arrangement com-.

prising, in combination with the wall of a casing,

a cupped washer with a shoulder abutting in a given direction againstthe edges of said opening in said casing-wall and with a cupped portionopening in the opposite direction, a resilient gasket fitting againstsaid washer in said cupped portion and having an opening therein inwhich a cable is adapted to fit, a relatively rigid bushing vpressedfrom sheet metal with a concave face fitting against said gasket andhaving. an opening therein substantially conforming to the surface ofsaid cable, a nipple against saidmetal bushing,

and means for clamping said nipple against said casing wall, thuscompressing said gasket between said cupped washer and said metalbushing and making a tight joint between said gasket and said cable.

2. A cable bushing arrangement for an electrical devicejcasing having awall with a cupped cable receiving opening therein, said arrangementcomprising, in combination with such a wall of a casing, a resilientgasket fitting against the cupped portion of said wall and having anopening therein in which a cable is adapted to fit, a relatively rigidbushing pressed from sheet metal with a concave surface fitting againstsaid gasket and having an opening therein substantially conforming tothe surface of said cable, a nipple against said metal bushing, andmeans for clamping said nipple against said casing wall, thuscompressingsaid gasketbetween said cupped wall and. said metal bushingand making a tight joint between said gasket and said cable.

-3. A cable bushing arrangement for a non-circular electric cable and anelectrical device casing having a wall with a cupped cable receivingopening therein, said arrangement comprising in combination with such acupped wall of va casing a resilient gasket fitting against said wall insaid cupped portion and having an opening therein in which the cable isadapted to fit, a relatively rigid bushing pressed from sheet metal witha concave surface fitting against said gasket and having an openingtherein substantially conforming to the surface of 'said cable, andmeans -for clamping said bushing against said casing wall, thuscompressing said *gasket between said cupped wall and said metal bushingand making a tight joint between said gasket and said cable.

HAROLD F. CROTTY.

